Space shuttle delivers power module to station

HOUSTON - Space shuttle Atlantis docked with the International Space Station 349km above the Earth today to deliver a new pair of power-producing solar arrays for the half-built research outpost.

Housed inside a 15,880-kg structural truss, the arrays are the first major addition to the station in nearly four years. Assembly of the US$100 billion ($158.37 billion) orbital complex came to an abrupt halt after the 2003 Columbia disaster.

Earlier today, shuttle commander Brent Jett gently pulsed steering jets to snap his ship's docking ring into a matching device attached to a berthing port on the station.

"Everything was dead-on," flight director Paul Dye later told reporters. "Brent just did a masterful job."

Once docked, Jett and his crewmates floated aboard and were warmly greeted by the resident station crew, commander Pavel Vinogradov, flight engineer Jeff Williams and the European Space Agency's Thomas Reiter.

"It's great to see all those people aboard," said deputy space station programme manager Kirk Shireman.

The crew had little time for sightseeing. They were given a safety briefing by the station crew, then dispersed to begin the transfer of their US$372 million cargo. It was a delicate undertaking with the 17.78-tonne truss passing just a fist's width from the payload bay sill.

The crew then prepared for a spacewalk scheduled to begin before dawn. To save time in the morning, spacewalkers Joe Tanner and Heidemarie Stefanyshyn-Piper donned oxygen masks to start purging nitrogen from their bodies.

In their partially pressurized spacesuits, astronauts are susceptible to developing dangerous bubbles in their bloodstreams, called the bends, unless the body's nitrogen is removed.

Tanner and Stefanyshyn-Piper then sealed themselves into the station's airlock and lowered the air pressure to continue conditioning their bodies overnight.

During their planned 6 1/2-hour spacewalk, the astronauts need to hook up 17 power and fluid lines after the truss is placed into position by the station's crane. They have also trained to manually bolt the girder into place if the automated system fails.

The new solar panels were to be unfolded after a second spacewalk set for Wednesday. The arrays will double the amount of electricity for the expanding International Space Station. When the station is complete, it will have four sets of the US-made arrays.

Nasa plans at least 14 more shuttle flights to complete the space outpost before the shuttle fleet is retired in 2010.

Space station construction was halted after Columbia disintegrated while returning to Earth on February 1, 2003, killing all seven of the astronauts on board.

Nasa put the shuttle programme on hold and spent more than US$1 billion to fix safety problems. It addressed particularly the issue of launch debris, which doomed Columbia by cracking the heat shield meant to protect it during the scorching reentry to the Earth's atmosphere.

Before reaching the station, the Atlantis astronauts used a sensor-laden boom to survey their ship for damage. Additional inspections were performed by the space station crew, which photographed the shuttle's belly before it docked.

Engineers on Monday decided they did not need additional inspections, which would have added a day to the mission.

"There was not much that anyone was concerned about," said flight director John Shannon.

- REUTERS